Crankshaft out of spec

Hello everyone,

I measured my crankshaft out of the 4G63 today. The manual states a the crankpin for the big ends of the connecting rods can be between 44.980-44.995mm

Those measure between 44.92mm and 44.94mm.

The main journals can be between 56.980-56.995mm

These all measure at 56,94 and one measures 56,92.

Can the crank be ground down or would i be better off buying a new crank?

It seems very weird that they all measure below the accepted size in the manual.

I calibrated my micrometer and checked it multiple times since it got me confused.

Car had a 100k miles / 180k kilometers before being torn down.

Any input is appriciated.

It seems like your crank has already been ground to undersize. So you need oversized bearing shells.

The average discrepancy of 0.05mm is ~0.002", and may be due to wear or a previous owner having the crankshaft journals 'polished'. How significant that is is going to depend on what the engine is going to be used for?

It may need to be re-ground but, if they're all round and unmarked, using 1 thou'" undersized bearing shells may bring them into an acceptable clearance range and, if the engine is going to be run hard at higher rpm, being a little on the high side may actually be advantagous - there are a bunch of gurus on that engine here who can better advise you.

I have checked a few dozens of 4g crankshafts and never had one with all journals below required specs. Most likely it's been already machined as Gord recons..

Thank you everyone for answering.

Does this mean it can be machined again or should i look for another crank?

Got a set of .025 over bearings, i'll see what spec that gives me.

Thanks again :)

It can be machined as long as you can find replacement bearings that will give you clearances required...